U.S. patent application number 11/600543 was filed with the patent office on 2007-05-24 for passenger protecting system for vehicle.
This patent application is currently assigned to DENSO Corporation. Invention is credited to Toshihito Nonaka, Satoru Takehara, Shingo Wanami.
Application Number | 20070114771 11/600543 |
Document ID | / |
Family ID | 38037939 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070114771 |
Kind Code |
A1 |
Wanami; Shingo ; et
al. |
May 24, 2007 |
Passenger protecting system for vehicle
Abstract
A passenger protecting system for a vehicle has a space defining
member which partially constructs a chassis of the vehicle and
defines therein an inner space deformable due to a collision of the
vehicle, a pressure detection member which is arranged in the inner
space to detect a pressure of air in the inner space, a temperature
detection member which is arranged in the inner space to detect a
temperature of air in the inner space, a determination unit, and a
passenger protection device for protecting a passenger in the
vehicle. The passenger protection device is actuated, when the
determination unit determines that there occurs the collision of
the vehicle based on a variation of the pressure and a variation of
the temperature.
Inventors: |
Wanami; Shingo;
(Kariya-city, JP) ; Nonaka; Toshihito;
(Chiryu-city, JP) ; Takehara; Satoru; (Obu-city,
JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO Corporation
Kariya-city
JP
|
Family ID: |
38037939 |
Appl. No.: |
11/600543 |
Filed: |
November 16, 2006 |
Current U.S.
Class: |
280/735 ;
180/274 |
Current CPC
Class: |
B60R 21/0136
20130101 |
Class at
Publication: |
280/735 ;
180/274 |
International
Class: |
B60K 28/10 20060101
B60K028/10; B60R 21/0136 20060101 B60R021/0136 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2005 |
JP |
2005-336099 |
Claims
1. A passenger protecting system for a vehicle, the passenger
protecting system comprising: a space defining member which defines
therein an inner space and partially constructs a chassis of the
vehicle, the inner space being deformable due to a collision of the
vehicle; a pressure detection member which is arranged in the inner
space to detect a pressure of air in the inner space; a temperature
detection member which is arranged in the inner space to detect a
temperature of air in the inner space; a determination unit for
determining whether or not there occurs the collision of the
vehicle, based on a variation of the pressure detected by the
pressure detection member and a variation of the temperature
detected by the temperature detection member; and a passenger
protection device for protecting a passenger in the vehicle, the
passenger protection device being actuated when the determination
unit determines that there occurs the collision of the vehicle.
2. The passenger protecting system according to claim 1, further
comprising a correction unit which determines a corrected pressure
by correcting the pressure corresponding to the temperature, the
pressure and the temperature being respectively detected by the
pressure detection member and the temperature detection member,
wherein the determination unit determines whether or not there
occurs the collision of the vehicle based on a variation of the
corrected pressure and the variation of the temperature.
3. The passenger protecting system according to claim 1, wherein a
surface of the space defining member for defining the inner space
is covered by a heat insulation material.
4. The passenger protecting system according to claim 1, wherein
the pressure detection member and the temperature detection member
are arranged in the inner space and positioned in the proximity to
each other.
5. The passenger protecting system according to claim 4, further
comprising a housing in which both the pressure detection member
and the temperature detection member are arranged, the housing
being positioned in the inner space.
6. The passenger protecting system according to claim 1, wherein
the space defining member is a door of the vehicle.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on a Japanese Patent Application
No. 2005-336099 filed on Nov. 21, 2005, the disclosure of which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a passenger protecting
system, which can be suitably used for a vehicle.
BACKGROUND OF THE INVENTION
[0003] Generally, as disclosed in JP-2-249740A, a vehicle can be
provided with a pressure sensor for a detection of a collision of
the vehicle. Specifically, an air tank which is closed is arranged
in a door of the vehicle. The pressure in the air tank is detected
by the pressure sensor. In the case where the pressure detected by
the pressure sensor is larger than or equal to a predetermined
threshold value, it is determined there occurs the collision
between the vehicle and an obstacle. Thus, a passenger protection
device of the vehicle such as an airbag and the like is
actuated.
[0004] Moreover, as disclosed in JP-2654428B2 (U.S. Pat. No.
5,748,075), a pressure of a predetermined space in the vehicle and
an acceleration of the vehicle which will vary due to a collision
of the vehicle are detected. Whether or not there occurs the
collision of the vehicle is repeatedly determined, respectively
based on the pressure and the acceleration. In this case, the
passenger protection device is actuated when the collision of the
vehicle has been determined.
[0005] Furthermore, as disclosed in JP-2004-513824A (U.S. Pat. No.
6,725,961), a temperature of a predetermined space defined in the
vehicle and the acceleration of the vehicle are detected. The
temperature and the acceleration will vary due to the collision of
the vehicle. Whether or not there occurs the collision of the
vehicle is repeatedly determined, respectively based on the
temperature and the acceleration. In this case, the passenger
protection device is actuated when the collision of the vehicle has
been determined.
[0006] According to JP-2654428B2 and JP-2004-513824A, the collision
determination accuracy is improved because the collision is
repeatedly determined.
[0007] However, according to JP-2654428B2, there is a difference
between the time period elapsed from the collision occurrence to
the collision detection based on the pressure, and that based on
the acceleration. For example, in the case of the collision at the
vehicle door, the collision is determined based on the pressure of
the inner space of the vehicle door and the acceleration of the
vehicle chassis. Generally, the vehicle door has a stiffness which
is not so high, to be readily deformed. That is, when there occurs
the collision between the door and the obstacle, the door is
firstly deformed and then the vehicle chassis moves.
[0008] Therefore, the acceleration of the vehicle will vary after
the pressure increase of the inner space of the vehicle door. Thus,
the collision is detected based on the pressure of the inner space,
and thereafter the collision is detected based on the acceleration
of the vehicle. In this case, the passenger protection device will
not be actuated, until the detection (which is later) of the
collision based on the acceleration.
[0009] Similarly, according to JP-2004-513824A, there is a
difference between the time period elapsed from the collision
occurrence to the collision detection based on the temperature, and
that based on the acceleration. In this case, the passenger
protection device will not be actuated, until the detection (which
is later) of the collision based on the acceleration.
SUMMARY OF THE INVENTION
[0010] In view of the above-described disadvantages, it is an
object of the present invention to provide a passenger protecting
system, in which a collision of a vehicle is detected at an earlier
time with an improved accuracy for an actuation of a passenger
protection device.
[0011] According to the present invention, a passenger protecting
system for a vehicle has a space defining member which partially
constructs a chassis of the vehicle and defines therein an inner
space deformable due to a collision of the vehicle, a pressure
detection member which is arranged in the inner space to detect a
pressure of air in the inner space, a temperature detection member
which is arranged in the inner space to detect a temperature of air
in the inner space, a determination unit and a passenger protection
device for protecting a passenger in the vehicle. The determination
unit determines whether or not there occurs the collision of the
vehicle, based on a variation of the pressure detected by the
pressure detection member and a variation of the temperature
detected by the temperature detection member. The passenger
protection device is actuated when the determination unit
determines that there occurs the collision of the vehicle.
[0012] In this case, the collision of the vehicle is repeatedly
determined, respectively based on the variation of the pressure and
the variation of the temperature in the inner space of the space
defining member which is fixed to the vehicle. Because the multiple
kinds of information is used for the determination of the vehicle
collision, the collision can be detected with an improved accuracy.
Thus, an unnecessary actuation of the passenger protection device
can be restricted.
[0013] Moreover, the variations of the pressure and the temperature
used for the collision determination are in substantial synchronism
with each other. In this case, the pressure and the temperature of
the inner space increase substantially simultaneously,
corresponding to the collision of the vehicle. That is, the time
period elapsed from the occurrence of the collision to the
determination (detection) of the collision based on the pressure
variation is substantially equal to, the time period elapsed from
the occurrence of the collision to the determination (detection) of
the collision based on the temperature variation. Therefore, the
collision can be detected at an earlier time, even when the
collision is determined according to the multiple kinds of
information.
[0014] Preferably, the passenger protecting system has a correction
unit which determines a corrected pressure by correcting the
pressure corresponding to the temperature. The pressure and the
temperature are respectively detected by the pressure detection
member and the temperature detection member. The determination unit
determines whether or not there occurs the collision of the vehicle
based on a variation of the corrected pressure and the variation of
the temperature.
[0015] In this case, the temperature in the inner space detected by
the temperature detection member is used for the determination of
the collision and for the correction of the pressure in the inner
space. Therefore, it is unnecessary to provide an additional
temperature detection member for detecting the ambient temperature
of the pressure detection member. Thus, the pressure detected by
the pressure detection member can be corrected with a reduced
cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other objects, features and advantages of the present
invention will become more apparent from the following detailed
description made with reference to the accompanying drawings, in
which:
[0017] FIG. 1 is a schematic view showing a door of a vehicle
according to a first embodiment of the present invention;
[0018] FIG. 2 is an enlarged partial sectional view showing a part
II in FIG. 1 according to the first embodiment;
[0019] FIG. 3 is a block diagram showing a passenger protecting
system according to the first embodiment;
[0020] FIG. 4 is a flow chart showing a determination process of a
determination unit of an airbag ECU according to the first
embodiment;
[0021] FIG. 5A is a graph showing a change of a corrected pressure
variation with the time elapsing in the case of a collision of the
door, and FIG. 5B is a graph showing a change of a temperature
variation with the time elapsing in the case of the collision of
the door; and
[0022] FIG. 6 is a block diagram showing a passenger protecting
system according to a second embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
First Embodiment
[0023] A passenger protecting system according to a first
embodiment of the present invention will be described with
reference to FIGS. 1-5. The passenger protecting system can be
suitably used for a vehicle, for example. The passenger protecting
system is provided with a sensor module 20, an airbag ECU 30, a
passenger protection device 40 and the like.
[0024] As shown in FIG. 1, the sensor module 20 includes a housing
21, a pressure detection member 22 (e.g., pressure sensor), a
temperature detection member 23 (e.g., temperature sensor) and a
communication IC 24. The sensor module 20 is arranged in an inner
space 13, which is defined in a space defining member (e.g., door
10). The space defining member can construct a part of the chassis
of the vehicle, and be deformable due to a collision of the
vehicle.
[0025] The door 10 has an inner panel 11 which is arranged at an
inner side of a passenger compartment of the vehicle, and an outer
panel 12 which is arranged at an outer side of the passenger
compartment. The inner space 13 is defined between the inner panel
11 and the outer panel 12.
[0026] In this case, a surface (e.g., right side in FIG. 1) of the
inner panel 11 and a surface (e.g., left side in FIG. 1) of the
outer panel 12 are covered by a heat insulation material. These
surfaces of the inner panel 11 and the outer panel 12 are
positioned at the inner side of the inner space 13. That is, the
most surfaces for defining the inner space 13 are covered by the
heat insulation material.
[0027] The housing 21 which is hollow is arranged in the inner
space 13 and attached to the inner panel 11. The housing 21 has an
opening 21a through which the space in the housing 21 is
communicated with the inner space 13 of the door 10. The opening
21a can be arranged at an opposite side of the housing 21 to the
inner panel 11 (passenger compartment). The pressure and the
temperature of air in the inner space 13 will vary due to the
collision at the door 10 of the vehicle, and be transferred from
the exterior of the housing 21 to the interior thereof through the
opening 21a.
[0028] The pressure sensor 22 is fixed in the housing 21 to detect
a variation of the pressure of air in the inner space 13 of the
door 10. Specifically, the pressure sensor 22 can have a sensor
chip 22a (i.e., pressure detection portion) and an amplification
circuit 22b (i.e., pressure correction unit).
[0029] The sensor chip 22a includes a diaphragm which can be
constructed of a silicon chip having a thin-walled center portion.
A diffusion resistance which constructs a Wheatstone bridge is
provided at the diaphragm. In the case where a pressure is applied
to the sensor chip 22a so that the diaphragm is deformed, a
potential difference between two ends (i.e., right end and left end
in FIG. 3) of the sensor chip 22a varies. Thus, the sensor chip 22a
outputs a signal of the potential difference between the two ends
thereof. Therefore, the variation .DELTA.P (caused by collision at
door 10, for example) of the pressure applied to the sensor chip
22a can be detected via the potential difference signal.
[0030] In this case, the signal of the pressure variation .DELTA.P
outputted by the sensor chip 22a is related to the ambient
temperature T of the sensor chip 22a (i.e., temperature T in
housing 21). That is, the pressure variation .DELTA.P detected by
the sensor chip 22a has a variability due to the ambient
temperature T.
[0031] The amplification circuit 22b is provided, to perform an
amplification correction process of the pressure variation .DELTA.P
detected by the sensor chip 22a so that a corrected pressure
variation .DELTA.P1 is obtained. In this case, the amplification
correction process includes an amplification process for
proportionally amplifying the pressure variation .DELTA.P outputted
by the sensor chip 22a, and a correction process based on the
temperature T detected by the temperature sensor 23. In the
correction process, the pressure variation .DELTA.P having been
amplified can be corrected so that the variability thereof due to
the ambient temperature T of the sensor chip 22a is eliminated. For
example, correction amounts (to be used in correction process)
corresponding to temperatures can be predetermined. Then, the
correction amount corresponding to the temperature T which is
practically detected by the temperature sensor 23 is, for example,
added to the pressure variation .DELTA.P detected by the sensor
chip 22a. In this case, the correction of the pressure variation
.DELTA.P can be also performed before the amplification
thereof.
[0032] According to this embodiment, the temperature sensor 23 is
fixed in the housing 21 and positioned near the pressure sensor 22,
to detect the temperature T and the temperature variation .DELTA.T
(caused by collision at door 10, for example) of air in the inner
space 13 of the door 10.
[0033] The communication IC 24, which can be arranged in the
housing 21, includes an A/D converter 24a and an interface 24b. The
corrected pressure variation .DELTA.P1 outputted from the pressure
sensor 22 and the temperature variation .DELTA.T outputted from the
temperature sensor 23 are inputted to the A/D converter 24a to be
A/D converted. Then, the corrected pressure variation .DELTA.P1 and
the temperature variation .DELTA.T which have been A/D-converted
are outputted to the airbag ECU 30 through the interface 24b.
[0034] The airbag ECU 30 can have an interface 31 and a
determination unit 32. The information outputted from the interface
24b of the communication IC 24 is inputted to the determination
unit 32 through the interface 31. Then, a determination process for
determining whether or not actuate the passenger protection device
40 is performed by the determination unit 32, based on the
information inputted thereto through the interface 31. A pressure
threshold Pth and a temperature threshold value Tth which are used
in the determination process can be beforehand memorized in the
determination unit 32.
[0035] The determination process of the determination unit 32 of
the airbag ECU 30 will be described with reference to FIG. 4. At
first, at step S1, it is determined whether or not the corrected
pressure variation .DELTA.P1 is larger than the pressure threshold
value Pth. In the case where the corrected pressure variation
.DELTA.P1 is smaller than or equal to the pressure threshold value
Pth (i.e., S1: No), the process shown in FIG. 4 will be repeated
from step S1.
[0036] On the other hand, in the case where the corrected pressure
variation .DELTA.P1 is larger than the pressure threshold value Pth
(i.e., S1: Yes), it is further determined at step S2 whether or not
the temperature variation .DELTA.T is larger than the temperature
threshold Tth.
[0037] In the case where the temperature variation .DELTA.T is
smaller than or equal to the temperature threshold value Tth (i.e.,
S2: No), the process shown in FIG. 4 will be repeated from step S1.
On the other hand, in the case where the temperature variation
.DELTA.T is larger than the temperature threshold value Tth (i.e.,
S2: Yes), it is determined that there occurs the collision with the
door 10 of the vehicle. Then, at step S3, the passenger protection
device 40 is actuated. Thereafter, the process shown in FIG. 4 is
repeatedly performed from step S1 when a predetermined time period
has elapsed, for example.
[0038] In this embodiment, the passenger protection device 40 can
include airbags, for example. The airbag can be deployed between
the door 10 and a passenger when the collision at the door 10 has
been determined.
[0039] Next, the operation of the passenger protecting system
according to this embodiment will be described with reference to
FIGS. 5A and 5B. FIG. 5A shows the change of the corrected pressure
variation .DELTA.P1 with the time elapsing, in the case of the
collision of the door 10. FIG. 5B shows the change of the
temperature variation .DELTA.T with the time elapsing, in the case
of the collision of the door 10.
[0040] Generally, the outer panel 12 of the door 10 has a stiffness
which is not so high. Therefore, in the case where there occurs a
collision at the outer panel 12, the outer panel 12 will be
deformed to the side of the inner panel 11. That is, immediately
after the occurrence of the collision of the outer panel 12, the
inner space 13 is deformed to become narrow. Thus, the pressure in
the inner space 13 increases.
[0041] Moreover, the temperature in the inner space 13 increases
due to an adiabatic change. That is, the pressure variation
.DELTA.P and the temperature variation .DELTA.T in the inner space
13 are in substantial synchronism with each other. As described
above, because the most surfaces which define the inner space 13
are covered by the heat insulation material, the heat in the inner
space 13 is restricted from radiating to the exterior of the inner
space 13. Thus, the temperature of air in the inner space 13 will
efficiently and substantially increase corresponding to the
increase of the pressure, and be used for the collision
determination.
[0042] In this case, the sensor chip 22a of the pressure sensor 22
detects the pressure variation .DELTA.P in the inner space 13,
which is transferred to the sensor chip 22a through the opening
21a. The temperature sensor 23 detects the temperature T and the
temperature variation .DELTA.T in the inner space 13 which is
transferred thereto through the opening 21a. Furthermore, the
corrected pressure variation .DELTA.P1 can be obtained via the
amplification circuit 22b of the pressure sensor 22, based on the
pressure variation .DELTA.P and the temperature T (i.e., ambient
temperature of pressure sensor 22). That is, the pressure variation
.DELTA.P detected by the sensor chip 22a (pressure detection
portion) is corrected via the temperature information outputted
from the temperature sensor 23 (temperature detection member).
[0043] According to this embodiment, the pressure sensor 22 and the
temperature sensor 23 are arranged in the housing 21 and positioned
in close proximity to each other. Therefore, the pressure variation
.DELTA.P detected by the sensor chip 22a of the pressure sensor 22
and the temperature variation .DELTA.T detected by the temperature
sensor 23 are in substantial synchronism with each other.
Accordingly, as shown in FIGS. 5A and 5B, the corrected pressure
variation .DELTA.P1 and the temperature variation .DELTA.T are in
substantial synchronism with each other.
[0044] In the case where the corrected pressure variation .DELTA.P1
is larger than the pressure threshold value Pth with reference to
FIG. 5A and the temperature variation .DELTA.T is larger than the
temperature threshold value Tth with reference to FIG. 5B, the
passenger protection device 40 will be actuated.
[0045] In this case, because the collision of the outer panel 12 of
the door 10 is repeatedly determined according to the corrected
pressure variation .DELTA.P1 and the temperature variation .DELTA.T
of the inner space 13 of the door 10, the determination accuracy
can be improved. Furthermore, the corrected pressure variation
.DELTA.P1 and the temperature variation .DELTA.T in the inner space
13 are in substantial synchronism with each other, so that the
collision can be determined at an earlier time. Moreover, in this
case, the corrected pressure variation .DELTA.P1 which has been
amplified and corrected by the amplification circuit 22b is used
for the determination of the collision. That is, the variability of
the signal outputted from the sensor chip 22a due to the ambient
temperature T thereof can be eliminated.
[0046] Moreover, because the pressure sensor 22 and the temperature
sensor 23 are arranged in the same housing 21, the synchronization
between the signals from the pressure sensor 22 and the temperature
sensor 23 can be improved. Furthermore, the space can be reduced
and the cost can be decreased.
Second Embodiment
[0047] A second embodiment of the present invention will be
described with reference to FIG. 6. In this case, the correction
process of the pressure variation .DELTA.P is performed by a
correction unit 33 of the airbag ECU 30. That is, the airbag ECU 30
calculates the corrected pressure variation .DELTA.P1 based on the
pressure variation .DELTA.P and the temperature T.
[0048] The passenger protecting system is provided with the sensor
module 20, the airbag ECU 30 and the passenger protection device
40. The sensor module 20 which is arranged in the inner space 13
has the housing 21, the pressure sensor 22, the temperature sensor
23 and the communication IC 24. The pressure sensor 22 having the
sensor chip 22a and the amplification circuit 22b is arranged in
the housing 21, to detect the pressure variation .DELTA.P of air in
the inner space 13 of the door 10. The temperature T and the
temperature variation .DELTA.T of the inner space 13 are detected
by the temperature sensor 23 which is arranged in the housing
12.
[0049] According to the second embodiment, the amplification
circuit 22b performs the amplification process of the pressure
variation .DELTA.P detected by the sensor chip 22a. At the
amplification process, the pressure variation .DELTA.P outputted
from the sensor chip 22a is proportionally amplified, for
example.
[0050] The airbag ECU 30 has the interface 31, the determination
portion 32, and the correction unit 33. The pressure variation
.DELTA.P having been amplified, the temperature T and the
temperature variation .DELTA.T (which are outputted from interface
24b of communication IC 24) are inputted to the correction unit 33
through the interface 31.
[0051] In this case, the pressure variation .DELTA.P having been
amplified is provided with the correction process by the correction
unit 33, based on the temperature T. At the correction process, the
pressure variation .DELTA.P having been amplified is processed so
that the variability thereof due to the ambient temperature T of
the sensor chip 22a is eliminated. For example, the correction
amounts corresponding to the temperatures can be beforehand set.
Then, the correction amount corresponding to the temperature T
which is practically detected by the temperature sensor 23 is, for
example, added to the pressure variation .DELTA.P having been
amplified so that the corrected pressure variation .DELTA.P1 is
calculated.
[0052] The determination unit 32 performs the determination process
for determining whether or not actuate the passenger protection
device 40, based on the temperature variation AT detected by the
temperature sensor 23 and the corrected pressure variation
.DELTA.P1 which is calculated by the correction unit 33. The
determination process can be performed similarly to that in the
above-described first embodiment with reference to FIG. 4. The
pressure threshold Pth and the temperature threshold value Tth
which are used in the determination process can be beforehand
memorized in the determination unit 32, for example.
[0053] In the case where the corrected pressure variation .DELTA.P1
and the temperature variation .DELTA.T are respectively larger than
the predetermined threshold values Pth and Tth, it is determined
that there occurs the collision at the door 10. Thus, the passenger
protection device 40 is actuated.
[0054] In this case, because the collision of the door 10 is
repeatedly determined according to the pressure variation and the
temperature variation of the inner space 13 of the door 10, the
determination accuracy can be improved. Furthermore, the pressure
variation and the temperature variation in the inner space 13 are
in substantial synchronism with each other, so that the collision
can be determined at an earlier time. Moreover, because the
corrected pressure variation .DELTA.P1 which has been amplified and
corrected is used for the determination of the collision, the
variability of the pressure variation .DELTA.P detected by the
sensor chip 22a due to the ambient temperature T can be
restricted.
[0055] About the passenger protecting system, what has not been
described in the second embodiment is the same with the first
embodiment.
Other Embodiments
[0056] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications will become apparent to those skilled in the
art.
[0057] For example, the space defining member for defining therein
the inner space 13 can be also constructed of a vehicle chassis
member (e.g., bumper) other than the door 10. In this case, the
space defining member having the inner space 13 therein is
deformable due to the collision of the vehicle.
[0058] Moreover, the heat insulation material can be also provided
for one of the inner surface (at inner side of inner space 13) of
the outer panel 13 and that of the inner panel 11.
[0059] Such changes and modifications are to be understood as being
in the scope of the present invention as defined by the appended
claims.
* * * * *